A New Design Strategy for Better Lithium Oxygen Batteries
Yale researchers have devised a method that brings marketable Li-O2 batteries closer to reality, improving both the batteries’ performance and the ability to study them.
In recent years, lithium-oxygen batteries have intrigued researchers with their potential. They can store at least two to three times the energy as lithium-ion batteries can, which are the current standard for consumer electronics, so laptops could theoretically run longer on a single charge and electric cars would drive farther.But researchers in the lab of Prof. André D. Taylor in Chemical & Environmental Engineering have devised a method that brings marketable Li-O2 batteries closer to reality, improving both the batteries’ performance and the ability to study them.
One of the big problems with Li-O2 batteries is their production of oxides, and its effect on the electrode. “What happens is the catalysts on the electrode surface gets buried with the oxide, so it’s no longer an effective catalyst,” Taylor said. Those solids build up on the electrodes, where the catalysts are placed, leading to an early battery death“The brittleness of the AAO membranes allows them to be cross-sectioned without destroying the well-defined pore structure, thus preserving the morphology of integrated lithium-oxide products,” Ryu said. “Therefore, the AAO membrane backbone offers a facile and effective way to observe cross-sectional features of the products at different electrochemical states and to investigate the growth mechanism for reaction.”
“PAN is a polymer, so it could break down if you’re doing recycling,” Taylor said. “But anodic aluminum oxide is a very stable oxide and it doesn’t lead to any unexpected side reactions. It works better and gives a better perspective on what’s happening electrochemically in the process.”
The modification not only led to a more efficient battery cell function, but it allowed the researchers to examine the composition of discharge products and the catalytic sites using Raman and X-ray photoelectron spectroscopy.
For future studies, Taylor said they will try different catalysts with the AAO membrane and explore new Li-O2 architectures.